Soon I must get another motherboard to accommodate 2 K20c and 2 680. As I recently discovered there can be issues when you mix multiple GPUs which have different PCI-e speeds. The K20s are PCI-e 2.0 while the 680’s are 3.0.
Also I may need the ability to swap out the 680s and use 2 Quadro 5000s for display, which are also PCI-e 2.0.
Ultimately I would like to get the maximum potential out of the setup, with the flexibility to do computation, as well as the occasional game play and high quality video output. I have a 1200 W power supply which should be enough, given I probably will not be using all four at once.
The system will be a dual-boot Windows 7 x64 Ubuntu 12.04 x64.
Is there anybody out there with a similar setup and is getting full potential out of the system? If so what specific motherboard/cpu combination are you using?